1. Field of the Invention
The present invention relates to a suspension board with circuit and a producing method thereof, to be specific, to a suspension board with circuit that is mounted on a hard disk drive, and a producing method thereof.
2. Description of Related Art
A suspension board with circuit mounted on a hard disk drive is mounted with a slider mounted with a magnetic head and allows the slider to be floated with a minute space with respect to a hard disk.
The slider is required to stably maintain a floating position (a position angle) to be fixed with respect to the hard disk without being influenced by moisture contained in the air, heat, and the like.
To meet the above-described requirement, for example, it has been suggested that in a suspension board including a metal board, an insulating layer that is formed thereon, a wire layer that is formed thereon, and a cover layer that is formed thereon, the coefficient of hygroscopic swelling of an insulating layer forming material and a cover layer forming material is set to be 0% RH to 30×10−6% RH and a difference therebetween is set to be 0 to 5×10−6% RH.